os2pm.gml

开放源码的编译器open watcom 1.6.0版的源代码

.chap *refid=os2pm Programming for OS/2 Presentation Manager
.*
:set symbol="winsys" value="Presentation Manager".
:set symbol="oprompt"    value=&prompt.
:set symbol="prompt"     value="[C:\]".
.*
.np
.ix 'OS/2 Presentation Manager'
Basically, there are two classes of &lang applications that can run in
a windowed environment.
.np
The first are those &lang applications that do not use any of the
&winsys API functions; they are strictly &lang applications that do
not rely on the features of a particular operating system.
.np
The second class of &lang applications are those that actually call
&winsys API functions directly.
These are applications that have been tailored for the &winsys
operating environment.
.np
It is assumed that the reader is familiar with the concepts of &winsys
programming.
.*
.section Porting Existing &lang Applications
.*
.np
.ix 'OS/2 PM' 'non-GUI applications'
Suppose you have a set of &lang applications that previously ran under
DOS and you now wish to run them under OS/2.
To achieve this, simply recompile your application and link with the
appropriate libraries.
Depending on the method with which you linked your application, it can
run in an OS/2 fullscreen environment, a PM-compatible window, or as a
Presentation Manager application.
An OS/2 fullscreen application runs in its own screen group.
A PM-compatible application will run in an OS/2 fullscreen environment
or in a window in the Presentation Manager screen group but does not
take direct advantage of menus, mouse or other features available in
the Presentation Manager.
A Presentation Manager application has full access to the complete set
of user-interface tools such as menus, icons, scroll bars, etc. However,
porting a console oriented application to Presentation Manager often
requires significant effort and a substantial redesign of the application.
.*
.if '&defwinos2' eq '1' .do begin
An application that was not designed as a windowed application (such
as a DOS application) can run as a Presentation Manager application.
This is achieved by a default windowing system that is optionally
linked with your application.
The following sections describe the default windowing system.
.do end
.*
.beglevel
.*
.if '&defwinos2' eq '1' .do begin
.im winio
.do end
.*
.section An Example
.*
.np
.ix 'OS/2 PM' 'non-GUI example'
Very little effort is required to port an existing &lang application
to OS/2.
Let us try to run the following sample program (contained in the file
.fi hello.&langsuff
.ct ).
.if '&lang' eq 'FORTRAN 77' .do begin
.millust begin
    print *, 'Hello world!'
    end
.millust end
.do end
.if '&lang' eq 'C' .do begin
.millust begin
#include <stdio.h>

int main( void )
/**************/
{
    printf( "Hello world!\n" );
    return( 0 );
}
.millust end
.do end
.if '&lang' eq 'C/C++' .do begin
.millust begin
#include <stdio.h>

int main( void )
/**************/
{
    printf( "Hello world!\n" );
    return( 0 );
}
.millust end
.np
An equivalent C++ program follows:
.millust begin
#include <iostream.h>

int main( void )
{
    cout << "Hello world" << endl;
    return( 0 );
}
.millust end
.do end
.np
First we must compile the file
.fi hello.&langsuff
by issuing the following command.
.millust begin
&prompt.&ccmd32 hello
.millust end
.np
Once we have successfully compiled the file, we can link it by issuing
the following command.
.millust begin
&prompt.&lnkcmd sys os2v2 file hello
.millust end
.np
It is also possible to compile and link in one step, by issuing the
following command.
.millust begin
&prompt.&wclcmd32 &sw.l=os2v2 hello
.millust end
.np
This will create a PM-compatible application.
If you wish to create a fullscreen application, link with the
following command.
.millust begin
&prompt.&lnkcmd sys os2v2 fullscreen file hello
.millust end
.*
.if '&defwinos2' eq '1' .do begin
.np
If you wish to use the default windowing system, you must recompile
your application and specify a special option, namely "bw".
.millust begin
&prompt.&ccmd32 -bw hello
.millust end
.np
We now link our application with the following command.
.millust begin
&prompt.&lnkcmd sys os2v2_pm file hello
.millust end
.endlevel
.*
.im pgdwlib
.do end
.el .do begin
.endlevel
.do end
.*
.section Calling Presentation Manager API Functions
.*
.np
.ix 'OS/2 PM' 'API calls'
It is also possible for a &lang application to create its own
windowing environment.
This is achieved by calling PM API functions directly from your &lang
program.
The techniques for developing these applications can be found in the
.book OS/2 Technical Library.
.*
.if '&lang' eq 'C/C++' .do begin
.np
A number of &lang include files (files with extension
.fi &hxt
.ct ) are
provided which define Presentation Manager data structures and
constants.
They are located in the
.fi &pathnam.&pc.h&pc.os2
directory.
These include files are roughly equivalent to the C/C++ header files that
are available with the IBM OS/2 Developer's Toolkit.
.np
A sample C/C++ Presentation Manager application is also located in the
.fi &pathnam.&pc.samples&pc.os2
directory.
It is contained in the files
.fi shapes.c
(C variant) and
.fi shapes.cpp
(C++ variant, nearly identical).
The file
.fi shapes.c
contains the following.
.code begin
#include <stdlib.h>

#define INCL_WIN
#define INCL_GPI
#include <os2.h>

.code break
int             SizeX;
int             SizeY;
HWND            FrameHandle;
HMQ             hMessageQueue;
HAB             AnchorBlock;

.code break
static int      Random( int high )
{
    return( ( (double)rand() / 32767 ) * high );
}

static void NewColor( HPS ps )
{
    GpiSetColor( ps, Random( 15 ) + 1 );
}

.code break
/* Draw a rectangular shape of random size and color at random position */
static void DrawEllipse(HWND hwndWindow)
{
    POINTL      ptl;
    HPS         ps;
    static int  Odd = 0;
    int         parm1,parm2;

.code break
    ps = WinGetPS( hwndWindow );
    ptl.x = Random( SizeX );
    ptl.y = Random( SizeY );
    GpiMove( ps, &ptl );
    ptl.x = Random( SizeX );
    ptl.y = Random( SizeY );
    parm1 = Random( 50 );
    parm2 = Random( 50 );
.code break
    if( Random( 10 ) >= 5 ) {
        NewColor( ps );
        GpiBox( ps, DRO_FILL, &ptl, 0, 0 );
        NewColor( ps );
        GpiBox( ps, DRO_OUTLINE, &ptl, 0, 0 );
    } else {
        NewColor( ps );
        GpiBox( ps, DRO_FILL, &ptl, parm1, parm2 );
        NewColor( ps );
        GpiBox( ps, DRO_OUTLINE, &ptl, parm1, parm2 );
    }
.code break
    Odd++;
    Odd &= 1;
    WinReleasePS( ps );
}

.code break
/* Client window procedure */
MRESULT EXPENTRY MainDriver( HWND hwnd, USHORT msg, MPARAM mp1, MPARAM mp2 )
{
    HPS         ps;
    RECTL       rcl;

    switch( msg ) {
.code break
    case WM_CREATE:
        /* Start a 150ms timer on window creation */
        WinStartTimer( AnchorBlock, hwnd, 1, 150 ) ;
        break;
    case WM_TIMER:
        /* Draw another ellipse on each timer tick */
        DrawEllipse( hwnd );
        return( 0 );
.code break
    case WM_SIZE:
        /* Remember new dimensions when window is resized */
        SizeX = SHORT1FROMMP( mp2 );
        SizeY = SHORT2FROMMP( mp2 );
        return( 0 );
    case WM_PAINT:
        /* Handle paint events */
        ps = WinBeginPaint( hwnd, NULL, NULL );
        WinQueryWindowRect( hwnd, &rcl );
        WinFillRect( ps, &rcl, CLR_WHITE );
        WinEndPaint( ps );
        return( 0 );
.code break
    }
    /* Let the default window procedure handle all other messages */
    return( WinDefWindowProc( hwnd, msg, mp1, mp2 ) );
}

.code break
int     main()
{
    ULONG       style;
    QMSG        qmsg;